American adults are retaining more of their teeth into their retirement years. Many prescription medications that are routinely used by the elderly are known to decrease salivary flow. This combination of circumstance should lead to an increased incidence of dental caries in the elderly that presumably will involve increases in the levels of the aciduric flora. We will document the salivary levels of the aciduric flora in the elderly and relate it to the degree of xerostomia and to the medications used. Little information exists on the bacterial flora associated with periodontal disease in the elderly, but one would assume that the same anaerobic, proteolytic flora that is found in younger individuals would be involved. Among the periodontopathic organisms, T. denticola, B. gingivalis, B. forsythus and C. gingivalis all exhibit trypsin-like activity that can be measured in the plaque by the hydrolysis of benzoyl-arginine-naphthylamide (BANA). We will evaluate BANA hydrolysis in the plaque and in the saliva as a means of identifying individuals at risk to periodontal disease. We will determine the effect of xerostomia on periodontal disease in the elderly. The xerostomia could predispose to other detrimental effects in the elderly. For example, in Sjogren's syndrome and in radiation xerostomia there is a selection for gram negative bacilli (GNB), which organisms under normal circumstances are rarely detectable in the saliva. This is an ominous change, as GNB in throat cultures are one of the risk factors associated with the development of an aspiration pneumonia in the elderly. Aspiration pneumonia is the fourth leading cause of death in the elderly. We will determine the prevalence of GNB in saliva and throat cultures and determine whether it can be related to the degree of xerostomia and to changes in the levels and/or proportions of either the aciduric and/or proteolytic flora. We will test the hypothesis that an increase in either the aciduric or proteolytic flora will predispose towards colonization of oral soft surfaces by the GNB. IF this be the case then measurements of these oral organisms or their products could serve to identify individuals at risk for colonization by GNB and thereby at risk of aspiration pneumonia involving these enterobacteriaciae.